410 SYSTEMATIC BOTANY, OR 



and pistil are in separate flowers, either on the same plant, or 

 on two or more different plants of the same species ; thus : — 



Class 21. Monoecia, includes plants where the stamens and pistil 

 are in separate flowers, but on the same individual, 

 as in the Euphorbia, Oak, Arum, &c. {Fig. 488.) 

 The name is derived from the Greek, and signifies 

 one household. 



Class 22. Dicecia, includes plants in which the stamens and 

 pistil are in separate flowers, situated on different 

 individuals of the same species, as in the Willow, 

 Hop, Hemp, &c. {Figs. 392, 393.) The name 

 signifies literally two households. 



Class 23. Polygamia, includes plants which have stamens and 

 pistil, separate in some flowers and united in others, 

 either on the same or on two or three different in- 

 dividuals of the same species, as in some Palms, &c. 

 {Fig. 394.) The name is derived from the Greek, 

 and signifies many marriages. 



The last class includes all Flowerless Plants, in which the 

 essential organs are said to be concealed ; hence its name 

 Cryptogamia. 



Class 24. Cryptogamia. This includes the Ferns {Figs. 158, 

 159), Mosses {Figs. 154, 155), Liverworts {Figs. 

 808 & 810). Liclicns, {Figs. 818, 819), Fungi {Figs. 

 150—152), and Alga {Fig. 153), all of which are 

 flowerless, and have concealed organs of reproduc- 

 tion. 



Orders. — The above Classes are subdivided into Orders as 

 follows : — 



The orders in the first thirteen classes, from IMonandria to 

 Polyandria, are founded on the number of styles, or of the 

 stigmas if the styles are absent. Their names are derived from 

 a combination of a Greek numeral with the termination gynia^ 

 meaning woman or female, and Avhich is used metaphorically 

 for pistil, in allusion to its functions in the process of fertiliza- 

 tion. Thus: — 



Order 1. Monogynia, includes all plants of any of the first 

 thirteen classes, Avhich have but one style to each 

 flower, as the Privet, Speedwell, Primrose, Arbutus, 

 &c. {Fig. 567.) 



Order 2. Digynia, includes those with two styles, as in most 

 Grasses, JJianthus, &c. {Fig. 587.) 



Order 3. Trigynia, includes those Avith three styles, as Silcne, 

 Jiiwtcx, &c. {Fig. 636.) 



